Abstract Unsteady aerodynamic phenomena appearing close to the stall boundary in axial fans and compressors have been subject of extensive investigations. A particular phenomenon known as “rotating instabilities” typically occurs tip region at highly loaded conditions is often linked blade vibrations. During rig engine testing, it usually identified by characteristic shape its pressure spectra....

This tutorial explains the surge phenomenon as well as the precursors of surge and the damage that surge can cause to the equipment. Then, methods to keep the compressor system from surge, i.e., modern surge control systems, are discussed. This includes the necessary instruments, algorithms used, as well as the piping layout required. Sizing considerations for valves and other system components...

We report a label-free assay for simultaneous optical manipulation and tracking of endogenous lipid droplets as actively transported cargoes in a living mammalian cell with sub-millisecond time resolution. Using an EM-CCD camera as a highly sensitive quadrant detector, we can detect steps of dynein- and kinesin-driven cargoes under known force loads. We can distinguish single and multiple motor...

Modeling and control for axial ow compression systems have received great attention in recent years. The objectives are to suppress rotating stall and surge, to extend the stable operating range of the compressor system, and to enlarge domains of attraction of stable equilibria using feedback control methods. The success of this research eld will signiicantly improve compressor performance and ...

Herein, the pressure-sensitive paint (PSP) was used to quantitatively investigate aerodynamic effect of an alula-like vortex generator, which is a bio-inspired passive flow control structure. The global pressure distributions on upper surface at different angles attack were measured determine strength sectional suction forces wing. An generator equipped leading edge wing enlarged area region (n...